Edit README for clarity

README.md

@@ -21,16 +21,19 @@ $ crystal deps
 
 ### Installing Postgres:
 
-On Arch:
+On Arch:  
-Install according to the [wiki](https://wiki.archlinux.org/index.php/PostgreSQL), then setup database with:
+Install according to the [wiki](https://wiki.archlinux.org/index.php/PostgreSQL#Installing_PostgreSQL):
-```bash
+
-$ ./setup.sh
-```
 On OSX:
 ```bash
 $ brew install postgres
 ```
 
+Then setup database with:
+```bash
+$ ./setup.sh
+```
+
 ## Usage:
 
 ```bash